Chromium compounds of ortho-hydroxy-azo-dyestuffs and process of making same



1 ITE?ST T capable of being chromed, particularly from.

discovery that this objection, which may Patented Sept; 27, 1932 r oF icE. I

FRITZ STRA'UIB, O F IBASEL, AND HERMANN= SCHNEIDER, OF RIEI-IEN, NEAR BASEL,

SWITZERLAND, ASSIGNORS '10 FIRM OF BASEL, SWITZERLAND r CHROMIUM coMPoUNDs or oR'rHo-HYDRoXY Azo-1)YEsTUrFsAND MAKING SAME SOCIETY OF CHEMICAL INDUSTRY IN BASLE,

rRooEss or No Drawing. Application filed June 7, 1928, Serial No. 283,731, and in s tzenaaa June 24, 1927.

The present invention relates to the manufacture ofchromium' compounds of orthohydroxy-azo-dyestufis. It comprises the process of making these new compounds, as Well as the new compounds themselves.

In the manufacture of chromium complexes from azo-dyestutfs containing groups ortho-hydroxy-azo-dyestulfs, by means of organic or inorganic chromium salts, 1t frequently happens that a part of the dyestuff is converted into chromium complexes which are useless, for they are sparingly soluble in water and cannot be converted, even by treatment with alkalies, into compounds capable of dyeing. v

The present invention is based upon the give rise to serious losses, is in many cases obviated by adding to the mixture of the azo-dyestuff to be chromed with the agent yielding chromium, which agent hitherto aling or neutralizing acids, organic salts in such a'quantity that after the chroming process is complete the reaction mixture contains organic salts. In many cases it is advantageous to add to the chroming mass besides j the mentioned additions also an inorganic salt. The chromation may further be carried out either in an open vessel or under pressure.

The following examples illustrate the invent-ion, the parts being by weight:

Emamplel A paste of 22 parts of the azo-dyestufi if from the nitrated diazo-compound of l-amino-Q-hydroXyna-phthalene- 4E sulfonic l acid and ,8-naphthol of the formula quired being about 6-8hours.

The very easily soluble chromium compound" is salted out while the liquid is hot salt =may be substituted for'the sodium ace? tate. g

V Zilwample 2 9.9 partsofthe dyestufl' from diazotized (i-sulfo;fbchloro ortho-amin0phen0l and ,8-

naphthylamine (sodium salt) of the formula Iii-N- V I 130380011 NHz t1 A r are dissolved in 1600 parts of water and 45.3

parts of crystallized sodium acetate are dis: solved in the solution; 40 parts, ofchromium oxide, in the form of chromium formate, dissolved in 400 parts of boiling water are added and are followed by 16.2 parts of formic acid of 85'p'er cent. strength. The whole, is boileduntil the soluble chromium compound has been formed. The dyestufi is obtained inthe I, V

usual manner.

H Example 3' 41.1 parts of the sodium salt' of the dye v in 800 parts of water while boiling. To this solution there are then added 15.2 parts of chromiumloxide in the form of chromium fluoride, and further 408 parts of crystallized sodium acetate and 595 parts of common salt.

. The reaction mixture is boiled for a long time 7 in a reflux apparatus, followed by filtering from chromium mud likely to be present. From the filtrate the dyestuff is separated by salting out. a

What we claim is 1. As an improvement in the manufacture ofchromium compounds of ortho-hydroxyazo-dyestuifs, the conversion of'the dyestufls into chromium complexes by'means of chromium salts in the presence of soluble salts of aliphatic monocarboxylic acids in such a quantity that afer the chroming process is complete the reaction mixture contains soluble salts of aliphatic monocarboxylic acids.

' 2. As an improvement in the manufacture of chromium compounds of ortho-hydroxyazo-dyestufis, the conversion of the dyestuffs w i into chromium complexesby means of chromlum salts 1n the presence of sodium acetate insuch a quanti'ty'that after the "chroming 5 dyestuffs obtained by conversion of thedyeprocess is complete the reaction mixture consuifs into chromium complexes by 'means of chromium salts in presence of sodium acetate in such a quantity that after the chromingprocess is complete-the reaction mixture contains sodium acetate, which dyestufis are more soluble than the products obtained without the addition claimed.

As new 'p s of manufacturefth chromium compounds ofortho-hydroxy-azo- 

